1. Field of the Invention
The present invention relates to artificial, i.e., non-natural, lighting systems, and more specifically to low voltage DC LED lighting systems.
2. Discussion of Related Art
Light-emitting diodes, or “LEDs”, are surging in popularity for lighting applications of all sorts. Although they have long held numerous technical advantages over more traditional types of artificial lighting such as incandescent bulbs, fluorescent lighting or halogen lighting, they were extremely expensive, and thus not widely used. Now that they are cost competitive, their technical superiority shines through. For example, LEDs are being used extensively in motor vehicles, and not just for illuminating instrument panels, but also as powerful light sources such as headlights. Similarly, LEDs are being used as street lights.
LEDs are low current devices. Thus, a large number of LED lights can be powered without drawing excessive amounts of electrical current. Since LEDs are driven by low voltages, the total electrical power consumed is very small compared to more conventional lighting sources.
Many American homes have outdoor decks or patios, and Americans enjoy them very much. Among other reasons, they enjoy the outdoors without having to venture far from home. In recent years, it has become possible and desirable to provide lighting of the deck or patio area so that people can enjoy their decks and patios after sunset.
Another popular feature in many American homes is the lighting of horizontal surfaces in the kitchen such as countertops, tables or “islands” from lights mounted above, such as from underneath kitchen cabinets. Such lights traditionally have been incandescent or fluorescent. With the advent of LEDs, and especially with the advent of thin, elongated strips featuring LEDs such as surface-mounted LEDs positioned every inch or so, it is now possible to use LED lights for this application. However, the homeowner or installer up to now has had to carefully measure the length of light strip that he needs, and place a custom order for this length, or has had to try to cut a stock length of LED lighting strip material to his desired length.
LEDs are low voltage devices, and they are also direct current (DC) devices. Thus, lighting systems that are designed as low voltage AC systems, require rectification before the current is supplied to the LED. Some low voltage AC systems have rectifier circuitry at each LED lamp or bulb. Power supplies that supply the current in DC form thus do not require componentry for rectification. In these systems, however, if the DC current is of the wrong (opposite) polarity than what the LED wants and requires, the LED will not function. In a string of LED lights, this problem can manifest itself in none of the LED lamps being lit, or only every other LED lamp being lit. One solution is to provide the LED lights with electrical connectors that are clearly marked to ensure the correct polarity. Unfortunately, it may be possible for the user or installer to plug the connectors together incorrectly.
The instant invention addresses and solves these problems.